The present invention relates to a two-dimensional error correction method using an outer parity added with respect to subblock data in the vertical direction, and an inner parity added with respect to either block identification data and subblock data or block identification data and the outer parity in the horizontal direction, and more particularly to a two-dimensional error correction method capable of outer parity decoding with respect to the block identification data, and a decoder suitable for utilizing the same.
A two-dimensional error correction method is an error correction method for securing data integrity, which is transmitted in a block-unit having a plurality of subblocks. Such a two-dimensional error correction method utilizes two types of error correction codes, one of which is related to a subblock (one-dimensional error correction code) and the other being related to a block (two-dimensional error correction code). Thus, a single error which occasionally will appear within any subblock (random errors) can be corrected by an error correction code in the one-dimensional level (relating to the subblocks), and successive errors of two or more subblocks (burst errors) can be corrected in the two-dimensional level (relating to the block).
A one-dimensional error correction code is produced by measuring either a subblock having block identification data ID and the subblock data, or a subblock having block identification data ID and a two-dimensional error correction code, which is then included in each subblock. A two-dimensional error correction code is produced by evaluating a byte-column formed of bytes in the same order within the subblock.
In the two-dimensional error correction method, the data has both one-dimensional and two-dimensional correction codes, while the block identification data ID has a one-dimensional error correction code only. As transmitted data maintains integrity with respect to random errors and burst errors by means of two error correction codes, it becomes preferable that the block identification data ID also has both error correction codes.